'assumption' originates from Latin, specifically the word 'assumptio,' where 'ad-' meant 'to' and 'sumere' meant 'take.'

'assumptio' transformed into the Old French word 'assumpcion,' and eventually became the modern English word 'assumption' through Middle English.

Initially, it meant 'the act of taking something for granted,' but over time it evolved into its current meanings of 'a belief accepted as true' and 'the act of taking on responsibility.'